A $30,000 reward is being offered for information leading to the arrest and conviction of the person responsible for the brutal stabbing deaths of a retired husband and wife who were attacked inside their Diamond Bar home last year.

The bodies of Cheng Long Wang, 60, and his 57-year-old wife, Mei Chu Chung, were found by a family friend on the morning of Oct. 20, 2016 who went to check on them after their family had not been able to reach them. The couple, known to friends as “David” and “Marian,” had been married for 30 years and were found gravely injured in separate rooms of their home in the 3300 block of Bent Twig Lane, the Los Angeles County Sheriff’s Department said at a news conference Wednesday.

The husband and wife had both been stabbed multiple times, were likely robbed and were pronounced dead at the scene, sheriff’s officials said.

“They didn’t deserve a death like this. They don’t rob, we don’t rob, we don’t steal,” Dr. Gary Wang, the couple’s son, said Wednesday. “They were just honest people living within their means.”

Dr. Wang said the death of his parents has been very difficult on his 4-year-old daughter who cries at night for her grandparents and misses video chatting with her grandmother.

Sheriff Jim McDonnell described the couple as the “classic example of an American success story.” They raised two children who became doctors, taught art lessons out of their home and were well-respected in the community, McDonnell said.

“They enjoyed life spending time with their grandchildren and their family in Taiwan,” McDonnell said. “They believed in helping others and would want someone in the community who might know something to step forward and help solve this brutal murder.”

The $30,000 reward is comprised of $20,000 approved by the Los Angeles County Board of Supervisors and $10,000 approved by city of Diamond Bar.

Anyone with information about the case was urged to call the Los Angeles County Sheriff’s Department Homicide Bureau at 323-890-5500.